1. Field of the Invention
This invention relates to electronic circuits, and more particularly, to equalization circuits.
2. Description of the Related Art
In modern electronic systems, signals may be transmitted over signal lines between or within integrated circuits (ICs). When transmitting between two ICs, signals may be conveyed on signal lines of a printed circuit board (PCB), via a cable, or by other means. Signals may also traverse relatively long distances within an IC over signal lines implemented on the IC die. When signals are conveyed between a source and a destination, some of the signal power may be lost. Accordingly, signals received at a destination may be provided to circuitry designed to prevent a loss of signal power.
Ensuring that signals are received at the destination with maximum or optimal signal power may include controlling a frequency response. Accordingly, receiver circuits may be implemented with equalization circuitry intended to provide a desired response across a range of frequencies. One type of commonly used circuit for performing equalization is a passive filter. A passive filter is implemented using passive components (e.g., resistors and capacitors), but not with active components (e.g., transistors). A passive filter may be implemented as a low-pass filter, a high-pass filter, or a band pass filter. A low-pass filter allows the passage of signals in a frequency range from 0 Hz up to a maximum frequency. A high-pass filter allows the passage of signals that are above a minimum frequency. A band pass filter allows the passage of signals between a minimum and a maximum frequency. Thus, using such filtering circuitry, passive equalization of circuitry may be performed on received signals.